ASME/ANSI B36.10/19
A 4 inches (100 mm) Schedule 80 pipe has an outside diameter of 4.500 inches ( 114.30 mm), a wall thickness of 0.337 inches (8.56 mm), giving a bore of 3.826 inches (97.18 mm) Carbon, Alloy and Stainless Steel Pipes - ASME/ANSI B36.10/19 - Imperial Units. ASME/ANSI B36.10/19 - Carbon, Alloy and Stainless Steel Pipes - Dimensions - Metric …